# Psychology Dictionary vs Katalis

The clearest difference is iOS requirement: Katalis at 13.0 against Psychology Dictionary's 17.0. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Psychology Dictionary sells 8 in-app purchases, starting at $4.99 per 7 days and Katalis sells 9 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

Psychology Dictionary ships an update every 4 weeks, Katalis monthly. The most recent releases landed on October 23, 2026 and September 28, 2026 respectively.

## The numbers

| Metric | Psychology Dictionary | Katalis |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (416 ratings)](https://appshunter.io/ios/app/psychology-dictionary/id1500147226/reviews)** | — |
| Number of ratings | **416** | — |
| Positive reviews | 88.9% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 4 weeks** | Monthly |
| Monetization | Free with in-app purchases | — |
| Size | 54 MB | 102 MB |
| Requires iOS | 17.0 | **13.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Nefarius Apps](https://appshunter.io/developer/1792473508) | [Behavioural Health Pty Ltd](https://appshunter.io/developer/1803274556) |

## What reviewers say

### Psychology Dictionary

[App page](https://appshunter.io/ios/app/psychology-dictionary/id1500147226)

Explore over 18,000 psychological terms with in-depth explanations and a pronunciation guide. This app serves as a comprehensive resource for students, professionals, and anyone interested in mental health and self-improvement.

**Highlights:** Extensive database of 18,000+ terms, In-depth explanations, Bookmark and favorite terms, Pronunciation guide, Regularly updated content

**Features:** macOS Compatibility, Family Sharing, Vision Pro support

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium | $4.99 | per 7 days |
| Premium | $4.99 | per 7 days |
| Premium weekly with discount | $9.99 | per 7 days |
| Premium | $9.99 | per month |
| Premium | $9.99 | per month |
| Premium | $14.99 | per month |
| Premium | $34.99 | per year |
| Premium | $74.99 | per year |

**What reviewers like**

- 📚 Comprehensive psychology terms
- 🤓 Useful for life and exams
- 👍 User-friendly interface
- 🌟 Great resource for students
- 💡 Detailed definitions

**What reviewers complain about**

- 💸 Expensive subscription
- 📺 Intrusive video ads
- 🙄 Ads interrupt typing
- ❌ Rate us function not working

**Reported bugs**

- Typo in definition of 'abuse' (foormal)
- App closes when looking up terms
- Video ads pop out while typing
- Rate us function doesn't work

**Requested features**

- Add small or key examples for each word
- Add horizontal view support for iPad (now implemented)


### Katalis

[App page](https://appshunter.io/ios/app/katalis/id6757698621)

**Features:** macOS Compatibility

**In-app purchases (9)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Living with Pain | $79.99 | one-time |
| Sleep Reset | $79.99 | one-time |
| Depression: Practical Skills | $79.99 | one-time |
| Anxiety: Practical Skills | $79.99 | one-time |
| ACT for Anxiety: ON DEMAND | $100.00 | one-time |
| ACT for Depression: ON DEMAND | $100.00 | one-time |
| ACT in Action: ON DEMAND | $100.00 | one-time |
| Focused ACT: Brief Interventions | $129.00 | one-time |
| Trauma Focused ACT | $300.00 | one-time |


## Frequently asked questions

### Is Psychology Dictionary free?

Psychology Dictionary is free to download, with in-app purchases available.

### Is Katalis free?

Katalis is free to download, with in-app purchases available.

### Do Psychology Dictionary or Katalis have ads?

Neither Psychology Dictionary nor Katalis shows ads.

### Which is updated more often, Psychology Dictionary or Katalis?

Psychology Dictionary ships an update every 4 weeks, and Katalis monthly. Most recently, Psychology Dictionary was updated on October 23, 2026 and Katalis on September 28, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*